Derivatives of 3- or 5-iodo pyridine



Patented June 1928 UNITED STATES cna'r nl'rn, or 3mm, 0mm.

nmuva'rms or aon Iono rrmmnn.

Io Application Illed Iovgmber 16, 1928, Serial Io. 147, 00, and in Auti-la'october 17, 1988. p

7 It is known (see for example (Qierman Patent No. 400191) that when chlorme acts on substituted pyridine derivatives, chlorination readily occurs in the nucleus, even in- 6 the cold.

This rule has also been confirmed by ap-' plicants, who have Obtained products chlorinated in the nucleus in' all cases of the action of free chlorine on pyridine deriva m tives, such for example, as 2-chlor-5-amidopyridine, 2-6-diaminopyridine, 2-am1no-5-,

'- mtropyrldine or 2-amino-5-bromopyridiner Confirmation of the rule has also been oh- 4 "tained in the chlorination of p ridine comu pounds containing iodine in t e 2-, 4- or 6- position; For example, if free chlorine be allowed to act on 2-iodo-5-aminopyridine in solution in glacial acetic acid, the mixture bein adequately cooled and energete Q ically sh en, an approximately quantitative yield of 2-iodo-3-chlor-5-aminopyridine, o the formula I isobtained.

It has now been unexpectedly discovered that the reaction proceeds in quite a differ. ent: manner when pyridine compounds containing iodine in the 3- or 5- position are l employed as the originating materials, there being, in these cases, no chlorination in the nucleus; whereas a satisfactory 'eld of the corresponding iodochlorides is 0 tained.

Thus, for example, 5-iodopyridine furnishes the iodochloride The iodochlorides ,which can be prepared according to the invention are distinguished by extremely powerful bactericidal properties, the active agents, during practical appli- 'product melts (undergoing 1 of chlorine;

and 2.-chlor-5-iodopyridine the iodochloride cation the liberated chlorine on the one hand and the decomposition-product itself (for example, the 2-chlor-5-iodopyridine) on the other. a

Moreover, the pyridyl iodochlorides preparable according to the invention consti v be transformed, by treatment with alkali,

into the corresponding iodosopyridine, of tllie'general formula, pyridyl-I=O. The res t1 iodosopyridines can then be transforme into the corresponding iodoxy-compounds of the general formula, pyridyl I=O,; for exam'ple,-by heating, with or without the presence of diluents such as water or water va our.

pounds prior to transformation into the iodoxy-compounds is unnecessary,

The following; exam les' Wlll serve to show how the process 0 this invention can be carried into eifect:

It has been ascerf tamed that isolation of the iodoso-com- 1. Chlorine is'passed into a solution of fl iodopyridine (cooled by means of ice water), until the liquid is saturated. The iodochloride comes down in the form of delicate ellow needles, which areonly very sparmgly soluble in the usual organic solvents in the cold, and moderately soluble in the warm, The yield is quantitative, and the decomposition) at 128-130. The resulting iodochloride gives off an The formula of the" obtained 2. Chlorine is passed, to saturation, into a solution of u-chlor-B'-iodopyridine, a quantitative yield of the corresponding'iodoohloproduct is intensive smell, recalling that ride being obtained in the form of a yellow crystalline powder meltin (with liberation of chlorine) at 104-106". he iodochloride is almost insoluble in the usual organic solvents and in water; and gives off a powerful smell recallingthat of chlorine. The'"formula of- .the obtained product is acetlc acid, but very sparingly soluble in Water a d the usual organic solvents. It

constitu s a powerful oxidizing agent. The formula of the obtained product is 4. Steam is blown 'throu h an aqueous suspension of u-chlor-fl' -io osopyridine, and carries ofi a-chlor-K-iodoxypyridine, whilst, on concentrating the steam-distillation residue, the a-chlor-B'-iodo pyridine crystal lizes out in the form of w ite needles. This compound detonates, with separation of iodine, at 210215. It is very sparingly soluble in the usual organic solvents, but soluble in glacial aceticacid. The compound is a powerful oxidising agent, and liberates chlorine when 'trgated with hydrochloric ..this 18th day of OOtObQI A. D. 1926.

v N/ What I claim is: 1. A- process for the production of new, 5 derivatives of pyridin, which consists in 45 causing chlorine to react on pyridin compounds which contain iodine in the 3 or 5'- position.

2. A process for the production of new derivatives of pyridin, which consists in causing chlorine to react on pyridin com pounds which contain iodine in the'3- or 5- position and converting the iodochloride obtained into the corresponding iodoso compounds by treatment-with alkali.

3. As a new product of manufacture a pyridin compound which contains the group v c1 in the 3- or 5- positio 4. As a new product of manufacture a pyridin compound which contains the group I I Km, 4 in the 3- or 5- position and, in addition,

other substitutin groups. 7

Signed at Ber in, Brandenburg, Prussia com Rim f 

